/*
 * [New BSD License]
 * Copyright (c) 2011-2012, Brackit Project Team <info@brackit.org>  
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Brackit Project Team nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.brackit.xquery.node.parser;

import org.brackit.xquery.util.log.Logger;
import org.brackit.xquery.xdm.DocumentException;
import org.brackit.xquery.xdm.Kind;
import org.brackit.xquery.xdm.Node;
import org.brackit.xquery.xdm.Stream;

/**
 * Streaming {@link SubtreeProcessor} for fragments.
 * 
 * @author Sebastian Baechle
 * 
 */
public class StreamSubtreeProcessor<E extends Node<E>> extends
		SubtreeProcessor<E> {
	private static final Logger log = Logger
			.getLogger(StreamSubtreeProcessor.class);

	private boolean displayNodeIDs;

	private final Stream<? extends E> scanner;

	public StreamSubtreeProcessor(Stream<? extends E> scanner,
			SubtreeListener<? super E>... listeners) {
		super(listeners);
		this.scanner = scanner;
	}

	public void process() throws DocumentException {
		try {
			E[] stack = (E[]) new Node[10];
			int stackSize = 0;
			E node = null;
			notifyBegin();

			while ((node = scanner.next()) != null) {
				if (stackSize == 0) {
					notifyBeginFragment();
				}

				// get kind of current node
				Kind kind = node.getKind();
				// handle closing tags and start new element if necessary
				if (kind != Kind.ATTRIBUTE) {
					while ((stackSize > 0)
							&& (!stack[stackSize - 1].isParentOf(node))) {
						E ancestor = stack[--stackSize];

						if (ancestor.getKind() == Kind.ELEMENT)
							notifyEndElement(ancestor);
						else
							notifyEndDocument();
					}
				}

				// call handler methods depending on node type
				if (kind == Kind.ELEMENT) {
					notifyStartElement(node);
					if (stackSize == stack.length) {
						E[] newElementStack = (E[]) new Node[((stackSize * 3) / 2) + 1];
						System.arraycopy(stack, 0, newElementStack, 0,
								stackSize);
						stack = newElementStack;
					}
					stack[stackSize++] = node;
				} else if (kind == Kind.ATTRIBUTE) {
					notifyAttribute(node);
				} else if (kind == Kind.TEXT) {
					notifyText(node);
				} else if (kind == Kind.COMMENT) {
					notifyComment(node);
				} else if (kind == Kind.PROCESSING_INSTRUCTION) {
					notifyProcessingInstruction(node);
				} else if (kind == Kind.DOCUMENT) {
					notifyBeginDocument();
					if (stackSize == stack.length) {
						E[] newElementStack = (E[]) new Node[((stackSize * 3) / 2) + 1];
						System.arraycopy(stack, 0, newElementStack, 0,
								stackSize);
						stack = newElementStack;
					}
					stack[stackSize++] = node;
				}

				if (stackSize == 0) {
					notifyEndFragment();
				}
			}

			while (stackSize > 0) {
				E ancestor = stack[--stackSize];

				if (ancestor.getKind() == Kind.ELEMENT) {
					notifyEndElement(ancestor);
				} else {
					notifyEndDocument();
				}

				if (stackSize == 0) {
					notifyEndFragment();
				}
			}

			notifyEnd();
		} catch (Exception e) {
			notifyFail();

			log.error(e);
			throw new DocumentException(e);
		} finally {
			scanner.close();
		}
	}
}